"As a kid growing up in California, I never thought that it would be possible to play professional football for 20 years in a country and a city that I knew nothing of," Calvillo said via CFL.ca.

The five-time all star quarterback had a lacklustre 2013 season, struggling with a concussion sustained in August and participating in just seven games. In limited action, he still passed for a team-leading 1,322 yards.

Calvillo retires as the all-time leading passer in professional football history, having thrown for a whopping 79,816 yards. The Utah State product holds several other CFL records, including most touchdown passes thrown (455), most pass completions (5,892) and most postseason passing yards thrown (2,470).

Nathan Denette/Associated Press

Calvillo retires as the all-time leading passer in pro football history.

Calvillo broke into the CFL in 1994 with the Las Vegas Posse, one of the handful of American teams that expanded into the league in the 1990s before ultimately failing (Calvillo retires as the last player to have played on an American CFL team). After one season in Las Vegas, he moved to the Hamilton Tiger-Cats for three seasons before finally settling in Montreal.

During his time with the Alouettes, Calvillo led the team to eight Grey Cup appearances, winning the championship three times, including back-to-back championships in 2009 and 2010. He also won the Grey Cup Most Outstanding Player award in 2002 while guiding Montreal to a 25-16 win over the Edmonton Eskimos.

Along the way, Calvillo broke the 5,000 passing yards plateau in seven seasons, and in 2012 he had a CFL-record eight-game streak of passing for 300 or more yards.

Calvillo's career will be remembered for his consistency and durability. He undoubtedly will go down in CFL history as one of the finest quarterbacks to ever play the game and will very shortly find himself in the Hall of Fame.